4th EucheMs chemistry congress

Poster Session 1
s877
chem. Listy 106, s587–s1425 (2012)
Poster session 1 - Physical, theoretical chemistry
P - 0 0 3 6
Coherent exCitAtion of neon in the
extreMe uLtrAvioLet reGiMe
C. rASChPiChLer 1 , J. PLenGe 1 , A. wirSinG 1 ,
B. wASSerMAnn 1 , e. rühL 1
1 Freie Universität Berlin, Institute of Chemistry and
Biochemistry, Berlin, Germany
Coherent excitation of atomic transitions is a general
phenomenon that may result in coherent transients. These are a
signature of interferences between resonant and non-resonant
excitation pathways. This fundamental process has been
investigated using ultrashort laser pulses in the near infrared
regime [1] . An extension of the investigation of these fundamental
processes from the optical to the extreme ultraviolet (xuv) regime
has become feasible with the development of ultrashort xuv light
sources. High-order harmonic generation is a well-established
technique for producing ultrashort radiation in the xuv range.
In this work we investigate the coherent excitation of a
superposition of Rydberg states in neon by the 13th harmonic of
an intense 804 nm pulse and the formation of a wave packet [2] .
We present pump-probe experiments performed on the 3d
manifold of neon where the 2p6 2p5 ( 2P ) 3d [1/2] and
3/2
2p6 2p5 ( 2P ) 3d [3/2] transitions are excited at 20.04 eV photon
3/2
energy. The temporal evolution of the excited wave packet is
probed by ionization with a time-delayed 804 nm pulse. We
demonstrate the control of the coherent transient excitation of
neon and the wave packet dynamics in the xuv regime using the
spectral phase of the 13th harmonic as a control parameter, where
the modulation of the phase is achieved by propagation of the xuv
pulse through a variable optical density of neon gas. The
experimental results indicate the possibility to control
fundamental coherent excitation processes in the xuv regime using
phase-shaped high-order harmonics.
references:
1. S. Zamith, J. Degert, S. Stock, and B. de Beauvoir, Phys.
Rev. Lett. 87, 033001 (2001).
2. J. Plenge, A. Wirsing, C. Raschpichler, B. Wassermann,
and E. Rühl, Faraday Discuss. 153, 361 (2011).
Keywords: Time-resolved spectroscopy; Photoelectron
spectroscopy;
4 th EucheMs chemistry congress
P - 0 0 3 7
roLe of exonS in StABiLizAtion of Protein
StruCture
i. roterMAn-KonieCznA 1 , M. PiwowAr 1 ,
M. BAnACh 2
1 Jagiellonian University - Medical College, Bioinformatics and
Telemedicine, Kraków, Poland
2 Jagiellonian University, Faculty of Physiscs Astronomy and
Applied Computational Science, Kraków, Poland
The role of exons can be interpreted on many aspects. One
of them is the relation of exons to the 3-D structure of protein. It
has been shown that fragments of the secondary structural forms
are not accordant with sequence fragments accordant with exons.
The relation between exon fragments and their structural
status in 3-D structural forms is under consideration. Particularly
the relation between tertiary structure of the protein and the
structure of exons present in particular protein has been analyzed.
The stabilization of tertiary structure is estimated on the basis of
hydrophobic core structure. The participation of exons in
hydrophobic stabilization is measured to reveal the role of each
exon-fragment.
The exons in selected proteins (100) were identified on the
basis of information in GenBank files taken from nucleotide
database in National Center of Biotechnology Information. The
amino acid sequence representing particular exon was identified.
The defined sequence fragments were localized in 3-D structural
forms of proteins (PDB).
The participation of each exon-fragment in the construction
of hydrophobic core was measured using the divergence entropy
calculation showing their differentiate role in the stabilization of
tertiary structure.
It was revealed that the presence of at least one exon, of
which the structure of polypeptide fragment is accordant with
expected ordered structure of hydrophobic core. It means that the
probable role of at least one exon is to generate the hydrophobic
core responsible for tertiary stabilization in proteins.
Acknowledgements: The financial support – Jagiellonian
University – Medical College grant system: K/ZDS/001531 and
K/ZDS/002907.
Keywords: exons; hydrophobic core; divergence entropy;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc